Effects of furfural on the respiratory metabolism of Saccharomyces cerevisiae in glucose-limited chemostats
Artikel i vetenskaplig tidskrift, 2003

Effects of furfural on the aerobic metabolism of the yeast Saccharomyces cerevisiae were studied by performing chemostat experiments, and the kinetics of furfural conversion was analyzed by performing dynamic experiments. Furfural, an important inhibitor present in lignocellulosic hydrolysates, was shown to have an inhibitory effect on yeast cells growing respiratively which was much greater than the inhibitory effect previously observed for anaerobically growing yeast cells. The residual furfural concentration in the bioreactor was close to zero at all steady states obtained, and it was found that furfural was exclusively converted to furoic acid during respiratory growth. A metabolic flux analysis showed that furfural affected fluxes involved in energy metabolism. There was a 50% increase in the specific respiratory activity at the highest steady-state furfural conversion rate. Higher furfural conversion rates, obtained during pulse additions of furfural, resulted in respirofermentative metabolism, a decrease in the biomass yield, and formation of furfuryl alcohol in addition to furoic acid. Under anaerobic conditions, reduction of furfural partially replaced glycerol formation as a way to regenerate NAD+. At concentrations above the inlet concentration of furfural, which resulted in complete replacement of glycerol formation by furfuryl alcohol production, washout occurred. Similarly, when the maximum rate of oxidative conversion of furfural to furoic acid was exceeded aerobically, washout occurred. Thus, during both aerobic growth and anaerobic growth, the ability to tolerate furfural appears to be directly coupled to the ability to convert furfural to less inhibitory compounds.

Författare

Ilona Sárvári Horváth

Chalmers, Institutionen för kemiteknik och miljövetenskap, Kemisk reaktionsteknik

Carl Johan Franzén

Chalmers, Institutionen för kemiteknik och miljövetenskap, Kemisk reaktionsteknik

Claes Niklasson

Chalmers, Institutionen för kemiteknik och miljövetenskap, Kemisk reaktionsteknik

Gunnar Lidén

Chalmers

Mohammad Taherzadeh Esfahani

Chalmers, Institutionen för kemiteknik och miljövetenskap, Kemisk reaktionsteknik

Applied and Environmental Microbiology

0099-2240 (ISSN) 1098-5336 (eISSN)

Vol. 69 7 4076-4086

Ämneskategorier

Mikrobiologi

Annan industriell bioteknik

DOI

10.1128/AEM.69.7.4076-4086.2003

PubMed

12839784